Manchester United midfielder Anderson has raised doubts over his future at the club after revealing he has attempted to leave Old Trafford on a number of occasions in the past.

Big things were expected from Anderson, 24, when he signed for United along with Nani in a big-money deal from Porto in 2007.

However, the Brazil international has struggled to cement his place in the Red Devils starting line-up, with injury often hampering his progress over the years.

When asked if he could return to Portugal, Anderson admitted he wants to leave United but is currently under contract.

"What can I say? I have three more years of contract, I have tried to leave many times and never succeeded to do so," he told Globo Esporte.

Anderson reportedly fell out with United manager Sir Alex Ferguson in 2009 after the Scot dropped him for the Community Shield clash with Chelsea. Ferguson was believed to have given his blessing for the midfielder to depart the club, but the player remains a useful member of the United squad

The former Porto man has made 18 appearances for United this season, scoring two goals.